Most of these changes have been incorporated into this fifth edition, the exception being the statement of the second law that remains unchanged. There is probably good reason for not following the pack in changing the statement of the second law. The currently vogue statement of the second law, in terms of the entropy function, is not consistent with the authors' "operational" approach of defining quantities by how they are measured, so the Clausius and Kelvin--Planck statements of the second law in terms of heat engines have been retained in this book. Numerous problems have been added on the application of thermodynamics to biological systems, mostly calculations of standard state free energies, enthalpies, and equilibrium constants for biochemical reactions. What I found lacking, however, is a domain of the biochemist's standard state, in which hydrogen ion concentration is taken to correspond to pH=7, which is more realistic than 1.0 mole/L in biological systems. For many biochemical reactions involving hydrogen ion the difference in standard state free energy of reaction is enormous.

As in earlier editions of this book, the subject is classical thermodynamics. Statistical thermodynamics is expressly excluded because its treatment draws on the results of quantum mechanics. It is interesting to read the explanation for an apparent exception to the third law that invokes the difference in low-temperature heat capacities of ortho- and para-hydrogen without getting into the statistical thermodynamics of hydrogen. Likewise, equations drawn from areas outside of thermodynamics are used without derivation, the Debye-Huckel equation, for example. This certainly is justified in a book on thermodynamics. But in the case of the Lewis and Randall rule, for estimating fugacities in real gas mixtures, I would have liked a fuller derivation/justification because the approximations lie squarely within thermodynamics.

This is an exceptionally well-written book. The style of writing is clear. There are many examples in the course of the development--not as separate subsections--and numerous topics and applications of thermodynamics.

Many of the problems included at the end of each chapter are new. Does this textbook possess any advantages over those massive physical chemistry books? I think so. If you are not interested in using the quantum chemistry, statistical mechanics, or any of the special topics that are included in most physical chemistry textbooks, the organization, content, and clarity of this book speak in its favor.